package com.example.java_chatroom.demo;

import java.util.*;

public class Demo03 {
    public static void main(String[] args) {
        ArrayList<Integer> arrayList = new ArrayList<Integer>();

        LinkedList<String> list = new LinkedList<>();
        Stack<Integer> stack = new Stack<>();
        Queue<Integer> queue = new LinkedList<>();
        queue.poll();

        Deque<Integer> deque = new LinkedList<>();

    }
}
